Hello! I know it is a long shoot, but I will try anyway...:) I have a car audio unit Alpine CD-E103BT. It is great, but I have one little problem. When I turn off subwoofer on that unit in subwoofer options menu, subwoofer works, but, when I turn it on, subwoofer doesn't work. Do You know what could be the problem? Sub is connected via amplifier to the head unit. Thanx!